The invention is directed to a plug-in connection for pipe and hose lines with reinforced material cross-section including a nozzle, which forms at least one catch shoulder, and a plug which can latch with the nozzle, the plug supporting at least one catch spring with catch legs which latch behind at least one of the catch shoulders of the nozzle.
A plug-in connection of this type is disclosed, for example, in EP 0 750 152 B1 by the same applicant. The entire content of this document is included in the presently disclosed invention.
The plug of conventional plug-in connections includes an inner sleeve and an outer sleeve oriented parallel to the inner sleeve, with the inner sleeve and the outer sleeve connected to each other in the region of a sealing ring.
A receiving space for insertion of a hose is formed between the two sleeves. The plug in the conventional embodiment is already formed with two walls in the region of the sealing ring.
It has been observed that the latching connection must be able to absorb relatively high insertion forces and axial pulling forces, in particular in the region of the catch spring and of the catch shoulder arranged opposite from the catch spring.
The latching shoulder in EP 0 750 151 B1 is formed in the region of the single-wall outer sleeve in connection with a catch spring opening disposed in the region of the nozzle.
Application of high separation forces to the plug-in connection poses the risk that the region of the catch spring opening facing the plug can fracture or even tear off in the region of the outer sleeve, which may cause the plug-in connection to disengage.
It is therefore an object of the invention to modify a plug-in connection of the aforedescribed type so that it can withstand significantly higher holding forces.